fix: exit error bug.

Gui/frelayGUI.cpp

@@ -8,7 +8,6 @@
 #include "Control/LogControl.h"
 
 static LogPrint* logPrint = nullptr;
-static QMutex logMut;
 
 frelayGUI::frelayGUI(QWidget* parent) : QMainWindow(parent), ui(new Ui::frelayGUI)
 {
@@ -28,9 +27,7 @@ frelayGUI::frelayGUI(QWidget* parent) : QMainWindow(parent), ui(new Ui::frelayGU
 
 frelayGUI::~frelayGUI()
 {
-    QMutexLocker locker(&logMut);
     delete ui;
-    logPrint = nullptr;
 }
 
 void frelayGUI::InitControl()
@@ -93,9 +90,7 @@ void frelayGUI::ControlMsgHander(QtMsgType type, const QMessageLogContext& conte
 {
     Q_UNUSED(context);
 
-    QMutexLocker locker(&logMut);
-
-    if (!logPrint) {
+    if (!qApp || !qobject_cast<frelayGUI*>(qApp->activeWindow())) {
         return;
     }